I tested with 3 VMs: three times - "Poweroff" of all VMs - each time a different VM was started, then the second and third generated this message. The commonality of all VMs is Ubuntu 20.0x and were created with the same VM template. As I said with 16.1, all three VMs were running at the same time.
In the meantime, I've uninstalled 16.2 and reinstalled 16.1. After the installation, I was able to use the VMs again.
Now I could compare what has changed on the file system under 16.2. With version 16.2 an option "scoreboard" is activated and this option creates a file in the directory.
If a second VM is started, this file appears to be accessible to the first VM.
2021-10-19T13:25:07.843Z In(05) vmx Vix: [mainDispatch.c:4206]: VMAutomation_ReportPowerOpFinished: statevar=0, newAppState=1871, success=1 additionalError=0
2021-10-19T13:25:07.845Z In(05) vmx VMXSTATS: Successfully created statsfile: vm.scoreboard
2021-10-19T13:25:07.846Z In(05) vmx VMXSTATS: Update Product Information: VMware Workstation 16.2.0 build-18760230 Release TotalBlockSize: 64
2021-10-19T13:25:07.846Z In(05) vmx HOST Windows version 10.0, build 19043, platform 2, ""
Now I am curious whether my assumption is correct! 